Madisonville, a town 1.5 miles up Tchefuncta River, has berths at public landings above and below the W side of the bridge.
There are several marinas above the highway bridge. Berths, electricity, gasoline, diesel fuel, water, ice, marine supplies, and launching ramps are available.
The Tchefuncta River flows into Lake Pontchartrain about 21 miles N of New Orleans. Commerce on the river is in shell and steel products. A dredged channel leads from the 10-foot depth in Lake Pontchartrain for about 12.2 miles up Tchefuncta River and its tributary, Bogue Falaya, to the town of Covington, LA. In 2001, the controlling depth was 6 feet across the bar, through the entrance; thence in 1994, 10 feet for about 1.7 miles to Madisonville, thence 4 feet to Abita River, thence 3 feet for about 1.1 miles.
The entrance is marked by a light, a lighted range, and daybeacons. State Route 22 highway bridge crossing the river at Madisonville has a swing span with a clearance of 1 foot. An overhead power cable with a clearance of 85 feet crosses the river about 6 miles above the bridge at Madisonville.
The twin fixed spans of Interstate Route 12 highway bridge with a clearance of 30 feet cross the river about 9.4 miles above the mouth.